[deliverable/linux.git] / arch / arm / mach-exynos4 / hotplug.c

/* linux arch/arm/mach-exynos4/hotplug.c
 *
 *  Cloned from linux/arch/arm/mach-realview/hotplug.c
 *
 *  Copyright (C) 2002 ARM Ltd.
 *  All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/io.h>

#include <asm/cacheflush.h>

#include <mach/regs-pmu.h>

extern volatile int pen_release;

static inline void cpu_enter_lowpower(void)
{
	unsigned int v;

	flush_cache_all();
	asm volatile(
	"	mcr	p15, 0, %1, c7, c5, 0\n"
	"	mcr	p15, 0, %1, c7, c10, 4\n"
	/*
	 * Turn off coherency
	 */
	"	mrc	p15, 0, %0, c1, c0, 1\n"
	"	bic	%0, %0, %3\n"
	"	mcr	p15, 0, %0, c1, c0, 1\n"
	"	mrc	p15, 0, %0, c1, c0, 0\n"
	"	bic	%0, %0, %2\n"
	"	mcr	p15, 0, %0, c1, c0, 0\n"
	  : "=&r" (v)
	  : "r" (0), "Ir" (CR_C), "Ir" (0x40)
	  : "cc");
}

static inline void cpu_leave_lowpower(void)
{
	unsigned int v;

	asm volatile(
	"mrc	p15, 0, %0, c1, c0, 0\n"
	"	orr	%0, %0, %1\n"
	"	mcr	p15, 0, %0, c1, c0, 0\n"
	"	mrc	p15, 0, %0, c1, c0, 1\n"
	"	orr	%0, %0, %2\n"
	"	mcr	p15, 0, %0, c1, c0, 1\n"
	  : "=&r" (v)
	  : "Ir" (CR_C), "Ir" (0x40)
	  : "cc");
}

static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
{
	for (;;) {

		/* make cpu1 to be turned off at next WFI command */
		if (cpu == 1)
			__raw_writel(0, S5P_ARM_CORE1_CONFIGURATION);

		/*
		 * here's the WFI
		 */
		asm(".word	0xe320f003\n"
		    :
		    :
		    : "memory", "cc");

		if (pen_release == cpu) {
			/*
			 * OK, proper wakeup, we're done
			 */
			break;
		}

		/*
		 * Getting here, means that we have come out of WFI without
		 * having been woken up - this shouldn't happen
		 *
		 * Just note it happening - when we're woken, we can report
		 * its occurrence.
		 */
		(*spurious)++;
	}
}

int platform_cpu_kill(unsigned int cpu)
{
	return 1;
}

/*
 * platform-specific code to shutdown a CPU
 *
 * Called with IRQs disabled
 */
void platform_cpu_die(unsigned int cpu)
{
	int spurious = 0;

	/*
	 * we're ready for shutdown now, so do it
	 */
	cpu_enter_lowpower();
	platform_do_lowpower(cpu, &spurious);

	/*
	 * bring this CPU back into the world of cache
	 * coherency, and then restore interrupts
	 */
	cpu_leave_lowpower();

	if (spurious)
		pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
}

int platform_cpu_disable(unsigned int cpu)
{
	/*
	 * we don't allow CPU 0 to be shutdown (it is still too special
	 * e.g. clock tick interrupts)
	 */
	return cpu == 0 ? -EPERM : 0;
}
Commit	Line	Data
7d30e8b3	1	/* linux arch/arm/mach-exynos4/hotplug.c
11adcc29 CY	2	*
	3	* Cloned from linux/arch/arm/mach-realview/hotplug.c
	4	*
	5	* Copyright (C) 2002 ARM Ltd.
	6	* All Rights Reserved
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/kernel.h>
	14	#include <linux/errno.h>
	15	#include <linux/smp.h>
911c29b0	16	#include <linux/io.h>
11adcc29 CY	17
	18	#include <asm/cacheflush.h>
	19
911c29b0 JM	20	#include <mach/regs-pmu.h>
911c29b0 JM	21
11adcc29 CY	22	extern volatile int pen_release;
11adcc29 CY	23
11adcc29 CY	24	static inline void cpu_enter_lowpower(void)
	25	{
	26	unsigned int v;
	27
	28	flush_cache_all();
	29	asm volatile(
	30	" mcr p15, 0, %1, c7, c5, 0\n"
	31	" mcr p15, 0, %1, c7, c10, 4\n"
	32	/*
	33	* Turn off coherency
	34	*/
	35	" mrc p15, 0, %0, c1, c0, 1\n"
ad849a22	36	" bic %0, %0, %3\n"
11adcc29 CY	37	" mcr p15, 0, %0, c1, c0, 1\n"
11adcc29 CY	38	" mrc p15, 0, %0, c1, c0, 0\n"
30b99d07	39	" bic %0, %0, %2\n"
11adcc29 CY	40	" mcr p15, 0, %0, c1, c0, 0\n"
11adcc29 CY	41	: "=&r" (v)
ad849a22	42	: "r" (0), "Ir" (CR_C), "Ir" (0x40)
11adcc29 CY	43	: "cc");
	44	}
	45
	46	static inline void cpu_leave_lowpower(void)
	47	{
	48	unsigned int v;
	49
	50	asm volatile(
	51	"mrc p15, 0, %0, c1, c0, 0\n"
e3d9c625	52	" orr %0, %0, %1\n"
11adcc29 CY	53	" mcr p15, 0, %0, c1, c0, 0\n"
11adcc29 CY	54	" mrc p15, 0, %0, c1, c0, 1\n"
ad849a22	55	" orr %0, %0, %2\n"
11adcc29 CY	56	" mcr p15, 0, %0, c1, c0, 1\n"
11adcc29 CY	57	: "=&r" (v)
ad849a22	58	: "Ir" (CR_C), "Ir" (0x40)
11adcc29 CY	59	: "cc");
	60	}
	61
d4450261	62	static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
11adcc29	63	{
11adcc29	64	for (;;) {
911c29b0 JM	65
	66	/* make cpu1 to be turned off at next WFI command */
	67	if (cpu == 1)
	68	__raw_writel(0, S5P_ARM_CORE1_CONFIGURATION);
	69
11adcc29 CY	70	/*
	71	* here's the WFI
	72	*/
	73	asm(".word 0xe320f003\n"
	74	:
	75	:
	76	: "memory", "cc");
	77
	78	if (pen_release == cpu) {
	79	/*
	80	* OK, proper wakeup, we're done
	81	*/
	82	break;
	83	}
	84
	85	/*
d4450261	86	* Getting here, means that we have come out of WFI without
11adcc29 CY	87	* having been woken up - this shouldn't happen
11adcc29 CY	88	*
d4450261 RK	89	* Just note it happening - when we're woken, we can report
d4450261 RK	90	* its occurrence.
11adcc29	91	*/
d4450261	92	(*spurious)++;
11adcc29 CY	93	}
	94	}
	95
	96	int platform_cpu_kill(unsigned int cpu)
	97	{
3c030bea	98	return 1;
11adcc29 CY	99	}
	100
	101	/*
	102	* platform-specific code to shutdown a CPU
	103	*
	104	* Called with IRQs disabled
	105	*/
	106	void platform_cpu_die(unsigned int cpu)
	107	{
d4450261 RK	108	int spurious = 0;
d4450261 RK	109
11adcc29 CY	110	/*
	111	* we're ready for shutdown now, so do it
	112	*/
	113	cpu_enter_lowpower();
d4450261	114	platform_do_lowpower(cpu, &spurious);
11adcc29 CY	115
	116	/*
	117	* bring this CPU back into the world of cache
	118	* coherency, and then restore interrupts
	119	*/
	120	cpu_leave_lowpower();
d4450261 RK	121
	122	if (spurious)
	123	pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
11adcc29 CY	124	}
	125
	126	int platform_cpu_disable(unsigned int cpu)
	127	{
	128	/*
	129	* we don't allow CPU 0 to be shutdown (it is still too special
	130	* e.g. clock tick interrupts)
	131	*/
	132	return cpu == 0 ? -EPERM : 0;
	133	}